Cup resistant to both slipping and tipping

ABSTRACT

A cup or glass design that prevents both slipping and tipping. The cup is shaped so that its bottom has both a region of high friction and a region of low friction. The region of high friction can be a set of small rubber feet or the like. The region of low friction can be the smooth cup surface. The two regions are juxtapositioned so that when the cup is sitting flat in its normal resting position, the region of high friction makes contact with the surface; however, if the cup is tipped, the region of high friction lifts off the surface allowing the region of low friction to contact the surface. This then causes the partially-tipped cup to slide rather than tip over. As it slides away from the source of the tipping force, the cup will then right itself by gravity and return to the normal resting position.

BACKGROUND Field of the Invention

The present invention relates generally to the field of slipping/tipping prevention and more particularly to a cup design that prevents both slipping and tipping over.

Description of the Problem

Cups have a tendency to slip on a smooth surface such as a tray or table. This effect is particularly acute on boats and ships where surfaces tilt as the vessel rolls. The effect also makes carrying several cups on a tray difficult.

Cups and glasses are also prone to tipping over when a relatively small force is applied to an upper surface. Our previous invention disclosed in U.S. Pat. No. 9,756,970 solved the problem of a coffee-style cup tipping over by providing three or more legs extending from the cup. These legs also served as handles. However, this previous invention does not alone solve the slipping problem.

It would be advantageous to have a cup (or glass or any other container) that would not slip on a smooth surface and was resistant to tipping over.

SUMMARY OF THE INVENTION

The present invention relates to a cup design that prevents both slipping and tipping. The cup is shaped so that its bottom has both a region of high friction and a region of low friction. The region of high friction can be a set of small rubber feet or the like. The region of low friction can be the smooth cup surface. The two regions are juxtapositioned so that when the cup is sitting flat in its normal resting position, the region of high friction makes contact with the surface; however, if the cup is tipped, the region of high friction lifts off the surface allowing the region of low friction to contact the surface. This then causes the partially-tipped cup to slide rather than tip over. As it slides away from the source of the tipping force, the cup then rights itself by gravity and returns to the normal resting position.

It is therefore a goal of the present invention to combine low and high friction surfaces on the base of a cup, glass or bowl to allow it to selectively grip and slide to avoid spilling under a variety of circumstances.

It is also a goal of the present invention to allow the anti-sliding feature to be combined with the anti-tipping cup of our previous invention disclosed in U.S. Pat. No. 9,756,970.

DESCRIPTION OF THE FIGURES

Attention is now directed to several drawings that illustrate features of the present invention.

FIG. 1 shows a prior art coffee-style cup prone to both sliding and tipping.

FIG. 2A shows the bottom of an embodiment of the present invention in a normal resting position.

FIG. 2B shows the embodiment of FIG. 2A in a partially tipped position.

FIG. 3 shows an embodiment of the present invention used with a standard coffee cup.

FIG. 4 shows a different embodiment of the present invention used with the three legged cup of our previous patent.

Several figures and illustrations have been provided to aid in understanding the present invention. The scope of the present invention is not limited to what is shown in the figures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a cup design that prevents sliding on a smooth surface and also prevents tipping. The bottom of the cup has both a region of high friction and a region of low friction. In the normal resting position, the region of high friction is in contact with the surface preventing sliding; in a partially tipped position (such as might occur the instant a force is applied to the top of the cup), the region of high friction lifts off the surface allowing the region of low friction to contact the surface. This causes the cup to slide rather than tip over. As it slides away from the source of the tipping force, the cup then rights itself by gravity and returns to its resting position.

There are multiple mechanisms by which a cup can spill its contents. It is generally recognized that, with rare exceptions, it is desirable for a cup not to slide on its supporting surface. This is especially true when cups are on surfaces that are non stationary such as on a boat or serving tray. However, it is also recognized that sliding on a supporting surface is preferable to tipping, and that these two goals can be in conflict.

FIG. 1 shows a prior art coffee-style cup 1. If the cup is impacted or pushed by a force 2, it is generally the case that the frictional force 3 that resists sliding also contributes to a torsional moment that induces the cup to tip over. Whether the cup slides or tips generally depends upon the height of its center of gravity, the amount of friction and the magnitude of the force. If the center of gravity is high enough, and the moment caused by the friction large enough, the cup tips rather than slides. Therefore, the frictional force that was desirable in preventing the cup from sliding now becomes undesirable in that it makes the cup more likely to tip. A goal of the present invention is to provide the desirable aspect of resisting sliding except in those cases where sliding would be preferable to the alternative, namely tipping.

The present invention accomplishes this by combining two different surfaces on the base of a cup which engage the supporting surface under different circumstances. As shown in FIGS. 2A, 2B, this is done by placing a high friction surface 6 such as rubber or the like at the bottom of the base of the cup 1 such that when the cup is sitting flat on the surface, the high friction area 4 is engaged with the supporting surface. A second surface 5 of lower friction next to the high friction surface 4 is positioned such that it is raised off of, and not directly in contact with, the supporting surface when the cup 1 is sitting flat on the supporting surface as shown in FIG. 2A. The outer side 7 of the low friction surface is typically curved.

When the cup is tilted as the result of applied force or impact as shown in FIG. 2B, the low friction surface 5 engages the supporting surface. As the cup 1 is tilted further, a point is reached that can be called a transition angle, where the high friction surface 4 will disengage from the supporting surface, and the entire contact area will be on the low friction surface 5. At the transition angle and beyond, the interface of the supporting surface and cup will be governed by the low friction surface 5. The result is that the force 3 (FIG. 1) that was causing the moment is significantly reduced, and so is the moment. The cup then begins to slide, since at this point, the pushing force 2 is almost always strong enough to overcome the static friction of the low friction surface 5. However, the partially tipped cup also experiences a counter moment caused by gravity that tends to right it. As the cup slides away from the source of the applied tipping force, this moment from gravity is now much greater than the tipping moment, the cup drops back down to its normal resting position again with the high friction surface 4 re-making contact with the supporting surface.

Embodiments of the present invention can also be used with a conventional cup base as shown in FIG. 3 or with the legs of the multi legged style cup of our previous patent as shown in FIG. 4. In either case, to facilitate sliding, the leading edge of the low friction surface can be rounded to facilitate sliding over surfaces that may be uneven including lumps or folds in tablecloths and place mats.

FIG. 3 shows the high friction devices 6 placed in indentations on the normal surface of the cup 1. This works as long as the high friction devices 6 lift off the supporting surface when the cup 1 is tipped.

FIG. 4 shows high friction devices 6 being used with each leg of the multi legged cup to provide a high friction surface 4. The leading edge of the leg can be rounded to provide the low friction surface 5 and rounded to prevent snagging as stated above. The outer side 7 of the low friction part of the leg is generally curved.

The high friction devices 6 can be rubber or any other material that will grip a smooth surface and prevent sliding. They can be attached to the cup 1 by gluing or by any other attachment method including being pushed into recesses in the cup bottom. The low friction region 5 is typically simply part of the cup bottom and can be porcelain, glass, smooth plastic or the like, usually the same material as the cup itself.

The present invention provides a solution to the problems of both slipping and tipping for any style cup, bowl, glass, pitcher or other liquid container. The present invention is useful for any container that may slide and/or tip over. It is particularly useful for tall glasses such as tall beer glasses, wine glasses and the like. It should therefore be noted, that while the word cup is used throughout this disclosure, word cup herein means any liquid container.

Several descriptions and illustrations have been presented to aid in understanding the present invention. One with skill in the art will realize that numerous changes and variations may be made without departing from the spirit of the invention. Each of these changes and variations is within the scope of the present invention. 

We claim:
 1. A cup bottom that prevents sliding and tipping comprising: a high friction region positioned to contact a supporting surface when the cup is in a normal resting position, the high friction region positioned to lift off of the supporting surface as the cup tips; a low friction region in proximity to the high friction region positioned so that the low friction region contacts the supporting surface when the high friction region lifts off the supporting surface as the cup tips.
 2. The cup bottom of claim 1 wherein the high friction region is rubber.
 3. The cup bottom of claim 1 wherein the high friction region is a plurality of rubber feet.
 4. The cup bottom of claim 1 wherein the high friction region is recessed into the cup bottom and the low friction region is shaped to cause the high friction region to lift off the supporting surface as the cup is tipped.
 5. The cup bottom of claim 1 wherein the low friction region is a smooth portion of the cup bottom.
 6. The cup bottom of claim 5 wherein the low friction region is a same material as the cup bottom.
 7. The cup bottom of claim 1 wherein the low friction region is ceramic.
 8. The cup bottom of claim 1 wherein an outer edge of the low friction region is curved.
 9. A cup having a cup bottom that resists both sliding and tipping comprising: a plurality of high friction areas positioned to contact a supporting surface when the cup is in a normal resting position, the high friction areas positioned to lift off of the supporting surface as the cup tips; a plurality of low friction areas located in proximity to the high friction areas; wherein, the low friction areas are shaped to cause the high friction areas to lift off of a supporting surface when the cup is partially tipped.
 10. The cup bottom of claim 9 wherein the high friction areas and low friction areas are located on legs extending outward from a cup body.
 11. The cup bottom of claim 9 wherein the low friction areas are a same material as the cup bottom.
 12. The cup bottom of claim 11 wherein the low friction areas are ceramic.
 13. A method of preventing a cup from sliding and tipping comprising placing a plurality of high friction areas on the cup bottom; placing a plurality of low friction areas on the cup bottom in proximity to the high friction areas, wherein, the low friction areas are shaped to cause the high friction areas to lift off of a supporting surface when the cup is partially tipped.
 14. The method of claim 13 wherein the high friction areas are rubber.
 15. The method of claim 14 wherein the high friction areas are a plurality of rubber feet.
 16. The method of claim 13 wherein the high friction areas are recessed into the cup bottom and the low friction areas are shaped to cause the high friction areas to lift off the supporting surface as the cup is tipped.
 17. The method of claim 13 wherein the low friction areas are smooth portions of the cup bottom.
 18. The method of claim 13 wherein the low friction areas are a same material as the cup bottom.
 19. The method of claim 18 wherein the low friction areas are ceramic.
 20. The method of claim 13 wherein the high friction areas and low friction areas are located on legs extending outward from a cup body. 